What is a tithe? Whom do we tithe to? Is it right to pay tithe to a Pastor or any minister of the church? The 10% of the income, is it gross or net?

Literally, the tithe is a tenth (Leviticus 27:32And concerning the tithe of the herd, or of the flock, even of whatsoever passeth under the rod, the tenth shall be holy unto the LORD.
See All...). As it applies to a gift to the Lord, it refers to a tenth of the increase. This increase can be income, or it can be the increase of a flock or other commodity. For instance, if a farmer has forty head of cattle and they give birth to ten calves in one year, the tithe is not on the fifty (40 + 10) but on the ten that make up the increase of the herd.

Though the tithe is found before the law (Genesis 14:20And blessed be the most high God, which hath delivered thine enemies into thy hand. And he gave him tithes of all.
See All...), under the law (Leviticus 27:30And all the tithe of the land, whether of the seed of the land, or of the fruit of the tree, is the LORD's: it is holy unto the LORD.
See All...), and after the law (Matthew 23:23Woe unto you, scribes and Pharisees, hypocrites! for ye pay tithe of mint and anise and cummin, and have omitted the weightier matters of the law, judgment, mercy, and faith: these ought ye to have done, and not to leave the other undone.
See All...), the epistles written to the churches in this age do not specifically mention it. This leaves us short on verses that teach us exactly what to do with the tithe. Some say that we are not required to give a tithe today. But even if this is so, the New Testament still teaches proportional giving. That is, those who receive more are to give more and those who receive less are to give less. If we do not use the tithe as a base, where else would we start? Though the epistles do not name the tithe, they do not tell us that its use has ceased either. It is just that the emphasis in the New Testament is on serving because of our love to God and not because of the laws he sets down. I do not believe that serious believers will stop at the tithe. They will give more. Consider these verses from the epistles:

1 Corinthians 16:2Upon the first day of the week let every one of you lay by him in store, as God hath prospered him, that there be no gatherings when I come.
See All... Upon the first day of the week let every one of you lay by him in store, as God hath prospered him, that there be no gatherings when I come.

Here, we are to give "as God hath prospered." If we base our giving on the tithe, that is exactly what will happen.

2 Corinthians 8:12For if there be first a willing mind, it is accepted according to that a man hath, and not according to that he hath not.
See All... For if there be first a willing mind, it is accepted according to that a man hath, and not according to that he hath not.

We give according to what we have and not according to what we do not have. This also is proportional giving.

Who receives the tithe? I think the best and safest way to give the tithe is through the church. The collection made in Corinth was to be gathered on the first day of the week when they were gathering for worship (1 Corinthians 16:1-2 [1] Now concerning the collection for the saints, as I have given order to the churches of Galatia, even so do ye. [2] Upon the first day of the week let every one of you lay by him in store, as God hath prospered him, that there be no gatherings when I come.
See All...). They must have brought the money to the church. On the other hand, a pastor is disqualified if he does his work for the sake of filthy lucre--the riches of this world (1 Timothy 3:3Not given to wine, no striker, not greedy of filthy lucre; but patient, not a brawler, not covetous;
See All...; 1 Peter 5:2Feed the flock of God which is among you, taking the oversight thereof, not by constraint, but willingly; not for filthy lucre, but of a ready mind;
See All...). If tithes are given directly to him, this takes all authority away from the church as a whole. This puts the preacher in a place where he can be tempted to do certain things just for the money. By giving him the income through the church, it protects him from certain temptations and properly uses the church--which was established by Christ. Even in the Old Testament, they brought the tithes into the storehouse (Malachi 3:10Bring ye all the tithes into the storehouse, that there may be meat in mine house, and prove me now herewith, saith the LORD of hosts, if I will not open you the windows of heaven, and pour you out a blessing, that there shall not be room enough to receive it.
See All...). From there it was distributed to the priests and Levites. I see no reason to change this.

Is the tithe on the gross or on the net? I tend to think that this question loses the very purpose of giving. We give as an expression of our love to the Lord. Giving is an act of worship--which means a declaration of the worth we place on Him. He does not ask for it all, but He does ask for a portion of what He has given us. Instead of answering this one directly, I will ask: what is God worth to you? You decide.